Linda Hopkin's, biggest moments have been reliving the life and songs of Bessie Simth in a Broadway production. But this weekend at Fort Dupont Park she showed that she's got another side - that of a red-hot disco mama.

After delivering a plaintive "Danny Boy" in slow, gospel style, Hopkens disrobed on stage - changing from flowing, sedate white gown to a black bathing suit with streamers.

She charged into a live-wire disco number, complete with bumps and grinds. "If the skinny ones can do it," the amply built singer said, "I can do it. You can see me. No pads!"

However, mostly she was like a slick Las Vegas lounge act. Hopkins hadn't sufficiently rehearsed with her musicians, and she offered only about a 40-minute program that included limp renditions of "Ain't Nobody's Business," "My Man" and "You've Been a Good Old Wagon."

The singer was outclassed by the superb work of the opening act, Dinizulu and his African Dancers, Drummers and Singers. The Long Island City-based group put on a vibrant, informative and fascinating program of ceremonial dances from West and Southern Africa. A narrator gave useful background before each dance.

The dancing was especially vital and fresh in the precision movements of several women who each used two canes to make accompanying rhythms.

Forthcoming performers in the free admission concert series, sponsored Melba Moore, the Alvin Ailey Repertory Dance Ensemble and Ramsey Lewis.